Abstract In this paper, Fe soft magnetic composites (SMCs) coated with MnO2 were prepared successfully by ball milling and following spark plasma sintering. The effect of MnO2 content on microstructure and magnetic properties for the Fe/MnO2 SMCs was investigated in detail. The analysis results show that a uniform MnO2 coating layer can be formed on the surface of the Fe particles via low speed ball milling with agate balls. When the MnO2 content increases from 0.0 wt% to 10.0 wt%, the thickness of the MnO2 coating layer exhibits a growth trend. As a consequence, the increased nonmagnetic phase leads to the magnetic dilution, finally resulting in the reduced saturation magnetization and deteriorated coercivity. Moreover, the enhanced resistivity induced by the increased thickness, significantly reduces the generation of the inter-particle eddy current, which leads to more stable permeability and lower total core loss at high frequencies. This study provides a novel insulating coating layer to reduce total core loss and is advantageous for the development of iron-based SMCs.

中文翻译：

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球磨制备MnO2包覆铁软磁复合材料的组织和磁性能

摘要 本文通过球磨和放电等离子烧结成功制备了MnO2包覆的铁软磁复合材料(SMCs)。详细研究了 MnO2 含量对 Fe/MnO2 SMC 微观结构和磁性能的影响。分析结果表明，用玛瑙球进行低速球磨可以在Fe颗粒表面形成均匀的MnO2涂层。当MnO2含量从0.0wt%增加到10.0wt%时，MnO2涂层的厚度呈现增长趋势。结果，增加的非磁性相导致磁性稀释，最终导致饱和磁化强度降低和矫顽力劣化。此外，由增加的厚度引起的电阻率增加，显着减少粒子间涡流的产生，从而导致更稳定的磁导率和更低的高频总磁芯损耗。该研究提供了一种新型绝缘涂层以降低总铁损，有利于铁基 SMC 的开发。